scholarly journals Female-to-male sex conversion in Ceratitis capitata by CRISPR/Cas9 HDR-induced point mutations in the sex determination gene transformer-2

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Roswitha A. Aumann ◽  
Irina Häcker ◽  
Marc F. Schetelig
Keyword(s):  
Sex Determination ◽  
Ceratitis Capitata ◽  
Point Mutations ◽  
Cost Effective ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Homology Directed Repair ◽  
Homozygous Line ◽  
Male Sex ◽  
The Cost

Abstract The Sterile Insect Technique (SIT) is based on the mass release of sterilized male insects to reduce the pest population size via infertile mating. Critical for all SIT programs is a conditional sexing strain to enable the cost-effective production of male-only populations. Compared to current female-elimination strategies based on killing or sex sorting, generating male-only offspring via sex conversion would be economically beneficial by doubling the male output. Temperature-sensitive mutations known from the D. melanogaster transformer-2 gene (tra2ts) induce sex conversion at restrictive temperatures, while regular breeding of mutant strains is possible at permissive temperatures. Since tra2 is a conserved sex determination gene in many Diptera, including the major agricultural pest Ceratitis capitata, it is a promising candidate for the creation of a conditional sex conversion strategy in this Tephritid. Here, CRISPR/Cas9 homology-directed repair was used to induce the D. melanogaster-specific tra2ts SNPs in Cctra2. 100% female to male conversion was successfully achieved in flies homozygous for the tra2ts2 mutation. However, it was not possible, to identify a permissive temperature for the mutation allowing the rearing of a tra2ts2 homozygous line, as lowering the temperature below 18.5 °C interferes with regular breeding of the flies.

scholarly journals Harnessing CRISPR-Cas9 for genome editing in Streptococcus pneumoniae D39V

2021 ◽  
Author(s):  
Dimitra Synefiaridou ◽  
Jan-Willem Veening
Keyword(s):  
Streptococcus Pneumoniae ◽  
Genome Editing ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Human Pathogen ◽  
Gram Positive Bacteria ◽  
Homology Directed Repair ◽  
Dna Fragment ◽  
Opportunistic Human Pathogen ◽  
Template Dna

CRISPR-Cas systems provide bacteria and archaea with adaptive immunity against viruses and plasmids by detection and cleavage of invading foreign DNA. Modified versions of this system can be exploited as a biotechnological tool for precise genome editing at a targeted locus. Here, we developed a replicative plasmid that carries the CRISPR-Cas9 system for RNA-programmable, genome editing by counterselection in the opportunistic human pathogen Streptococcus pneumoniae. Specifically, we demonstrate an approach for making targeted, marker-less gene knockouts and large genome deletions. After a precise double-stranded break (DSB) is introduced, the cells’ DNA repair mechanism of homology-directed repair (HDR) pathway is being exploited to select successful transformants. This is achieved through the transformation of a template DNA fragment that will recombine in the genome and eliminate recognition of the target of the Cas9 endonuclease. Next, the newly engineered strain can be easily cured from the plasmid that is temperature-sensitive for replication, by growing it at the non-permissive temperature. This allows for consecutive rounds of genome editing. Using this system, we engineered a strain with three major virulence factors deleted. The here developed approaches could be potentially transported to other Gram-positive bacteria. Importance Streptococcus pneumoniae (the pneumococcus) is an important opportunistic human pathogen killing over a million people each year. Having the availability of a system capable of easy genome editing would significantly facilitate drug discovery and efforts in identifying new vaccine candidates. Here, we introduced an easy to use system to perform multiple rounds of genome editing in the pneumococcus by putting the CRISPR-Cas9 system on a temperature-sensitive replicative plasmid. The here used approaches will advance genome editing projects in this important human pathogen.

scholarly journals Genetic analysis of an intersex allele (ix5) that regulates sexual phenotype of both female and male Drosophila melanogaster

2002 ◽  
Vol 80 (1) ◽  
pp. 7-14 ◽  
Author(s):  
M. ACHARYYA ◽  
R. N. CHATTERJEE
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis ◽  
Sex Determination ◽  
Male Genitalia ◽  
Point Mutations ◽  
Normal Male ◽  
Sexual Phenotype ◽  
Sex Comb ◽  
Male Sex ◽  
Courtship Activity

An allele of intersex (ix5) of Drosophila melanogaster has been characterized. The genetic analysis of the allele demonstrated that like other point mutations of ix, the ix5 allele also transformed diplo-X individuals into intersexes. The ix5 mutation also affects the arrangement of sex comb bristles on the forelegs of males, although they had morphologically nearly normal male genitalia. They often fail to display a sustained pattern of courtship activity when tested. Orcein-stained squash preparations of testes from ix5 males revealed a defect in spermatogenesis. Our results, taken together with those of McRobert & Tompkins (1985), indicate that the ix+ gene also functions in male sex determination.

scholarly journals Harnessing CRISPR-Cas9 for genome editing in Streptococcus pneumoniae

2020 ◽  
Author(s):  
Dimitra Synefiaridou ◽  
Jan-Willem Veening
Keyword(s):  
Streptococcus Pneumoniae ◽  
Genome Editing ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Human Pathogen ◽  
Gram Positive Bacteria ◽  
Homology Directed Repair ◽  
Dna Fragment ◽  
Opportunistic Human Pathogen ◽  
Template Dna

AbstractCRISPR systems provide bacteria and archaea with adaptive immunity against viruses and plasmids by detection and cleavage of invading foreign DNA. Modified versions of this system can be exploited as a biotechnological tool for precise genome editing at a targeted locus. Here, we developed a novel, replicative plasmid that carries the CRISPR-Cas9 system for RNA-programmable, genome editing by counterselection in the opportunistic human pathogen Streptococcus pneumoniae. Specifically, we demonstrate an approach for making targeted, marker-less gene knockouts and large genome deletions. After a precise double-stranded break (DSB) is introduced, the cells’ DNA repair mechanism of homology-directed repair (HDR) pathway is being exploited to select successful transformants. This is achieved through the transformation of a template DNA fragment that will recombine in the genome and eliminate recognition of the target of the Cas9 endonuclease. Next, the newly engineered strain, can be easily cured from the plasmid that is temperature-sensitive for replication, by growing it at the non-permissive temperature. This allows for consecutive rounds of genome editing. Using this system, we engineered a strain with three major virulence factors deleted. The here developed approaches should be readily transportable to other Gram-positive bacteria.ImportanceStreptococcus pneumoniae (the pneumococcus) is an important opportunistic human pathogen killing over a million people each year. Having the availability of a system capable of easy genome editing would significantly facilitate drug discovery and vaccine candidate efforts. Here, we introduced an easy to use system to perform multiple rounds of genome editing in the pneumococcus by putting the CRISPR-Cas9 system on a temperature-sensitive replicative plasmid. The here used approaches will advance genome editing projects in this important human pathogen.

Temperature and non-aromatizable androgens: a common pathway in male sex determination in a turtle with temperature-dependent sex determination?

1996 ◽  
Vol 149 (3) ◽  
pp. 457-463 ◽  
Author(s):  
D Crews ◽  
A R Cantú ◽  
J M Bergeron
Keyword(s):  
Sex Determination ◽  
Incubation Temperature ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Temperature Dependent ◽  
Dose Response Relationship ◽  
Common Pathway ◽  
Slider Turtle ◽  
Male Sex ◽  
Incubation Temperatures

Abstract This study addressed the hypothesis that, in the red-eared slider turtle, Trachemys scripta, non-aromatizable androgens are the physiological equivalent of temperature in determining male development. In the first experiment, eggs were treated in the middle of the temperature-sensitive period with 1·0 or 10·0 μg androsterone, 5α-dihydrotestosterone, 3α-androstanediol, or 3β-androstanediol, while at an all-male, male-biased, or one of two female-biased incubation temperatures. In the second experiment, eggs were treated with the same dosages of dihydrotestosterone at different stages of embryonic development while at a male-biased, threshold, or a female-biased incubation temperature. Results of experiment one indicated that hormone-induced masculinization is specific to non-aromatizable androgens. Results of experiment two indicated that the sensitivity to dihydrotestosterone corresponds to the temperature-sensitive window during development. Further, there is a dose–response relationship but no apparent synergism between exogenous dihydrotestosterone and incubation temperature. When considered with other research, it is suggested that non-aromatizable androgens and their products are involved in the initiation of male sex determination whereas oestrogens and their aromatizable androgen precursors are involved in the initiation of female sex determination. Journal of Endocrinology (1996) 149, 457–463

scholarly journals New Temperature-Sensitive Alleles of ftsZ in Escherichia coli

2005 ◽  
Vol 187 (1) ◽  
pp. 358-365 ◽  
Author(s):  
Stephen G. Addinall ◽  
Elaine Small ◽  
Duncan Whitaker ◽  
Shane Sturrock ◽  
William D. Donachie ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Point Mutations ◽  
Ring Formation ◽  
Single Amino Acid ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Nonpermissive Temperature ◽  
Z Ring

ABSTRACT We isolated five new temperature-sensitive alleles of the essential cell division gene ftsZ in Escherichia coli, using P1-mediated, localized mutagenesis. The five resulting single amino acid changes (Gly109→Ser109 for ftsZ6460, Ala129→Thr129 for ftsZ972, Val157→Met157 for ftsZ2066, Pro203→Leu203 for ftsZ9124, and Ala239→Val239 for ftsZ2863) are distributed throughout the FtsZ core region, and all confer a lethal cell division block at the nonpermissive temperature of 42°C. In each case the division block is associated with loss of Z-ring formation such that fewer than 2% of cells show Z rings at 42°C. The ftsZ9124 and ftsZ6460 mutations are of particular interest since both result in abnormal Z-ring formation at 30°C and therefore cause significant defects in FtsZ polymerization, even at the permissive temperature. Neither purified FtsZ9124 nor purified FtsZ6460 exhibited polymerization when it was assayed by light scattering or electron microscopy, even in the presence of calcium or DEAE-dextran. Hence, both mutations also cause defects in FtsZ polymerization in vitro. Interestingly, FtsZ9124 has detectable GTPase activity, although the activity is significantly reduced compared to that of the wild-type FtsZ protein. We demonstrate here that unlike expression of ftsZ84, multicopy expression of the ftsZ6460, ftsZ972, and ftsZ9124 alleles does not complement the respective lethalities at the nonpermissive temperature. In addition, all five new mutant FtsZ proteins are stable at 42°C. Therefore, the novel isolates carrying single ftsZ(Ts) point mutations, which are the only such strains obtained since isolation of the classical ftsZ84 mutation, offer significant opportunities for further genetic characterization of FtsZ and its role in cell division.

The IBM-PC in electron microscopy

1996 ◽  
Vol 54 ◽  
pp. 612-613
Author(s):  
James F. Mancuso
Keyword(s):  
Head Start ◽  
Image Acquisition ◽  
Cost Effective ◽  
Financial Applications ◽  
Number Of Factors ◽  
Instrument Control ◽  
The Cost ◽  
Training And Support ◽  
Control Image ◽  
Ibm Pc

IBM PC compatible computers are widely used in microscopy for applications ranging from control to image acquisition and analysis. The choice of IBM-PC based systems over competing computer platforms can be based on technical merit alone or on a number of factors relating to economics, availability of peripherals, management dictum, or simple personal preference.IBM-PC got a strong “head start” by first dominating clerical, document processing and financial applications. The use of these computers spilled into the laboratory where the DOS based IBM-PC replaced mini-computers. Compared to minicomputer, the PC provided a more for cost-effective platform for applications in numerical analysis, engineering and design, instrument control, image acquisition and image processing. In addition, the sitewide use of a common PC platform could reduce the cost of training and support services relative to cases where many different computer platforms were used. This could be especially true for the microscopists who must use computers in both the laboratory and the office.

Sonographically guided, transcatheter foam sclerotherapy of the great saphenous vein

Phlebologie ◽  
2007 ◽  
Vol 36 (06) ◽  
pp. 309-312 ◽  
Author(s):  
T. Schulz ◽  
M. Jünger ◽  
M. Hahn
Keyword(s):  
Saphenous Vein ◽  
Great Saphenous Vein ◽  
Clinical Stage ◽  
Clinical Signs ◽  
Cost Effective ◽  
Duplex Sonography ◽  
Foam Sclerotherapy ◽  
Average Loss ◽  
One Year ◽  
The Cost

Summary Objective: The goal of the study was to assess the effectiveness and patient tolerability of single-session, sonographically guided, transcatheter foam sclerotherapy and to evaluate its economic impact. Patients, methods: We treated 20 patients with a total of 22 varicoses of the great saphenous vein (GSV) in Hach stage III-IV, clinical stage C2-C5 and a mean GSV diameter of 9 mm (range: 7 to 13 mm). We used 10 ml 3% Aethoxysklerol®. Additional varicoses of the auxiliary veins of the GSV were sclerosed immediately afterwards. Results: The occlusion rate in the treated GSVs was 100% one week after therapy as demonstrated with duplex sonography. The cost of the procedure was 207.91 E including follow-up visit, with an average loss of working time of 0.6 days. After one year one patient showed clinical signs of recurrent varicosis in the GSV; duplex sonography showed reflux in the region of the saphenofemoral junction in a total of seven patients (32% of the treated GSVs). Conclusion: Transcatheter foam sclerotherapy of the GSV is a cost-effective, safe method of treating varicoses of GSV and broadens the spectrum of therapeutic options. Relapses can be re-treated inexpensively with sclerotherapy.

A Digital Economy Model for Talent Prediction Data Analytic

2019 ◽  
Vol 2 (4) ◽  
pp. 260-266
Author(s):  
Haru Purnomo Ipung ◽  
Amin Soetomo
Keyword(s):  
Business Model ◽  
Industrial Revolution ◽  
Technology Innovation ◽  
Cost Effective ◽  
Sharing Economy ◽  
Token Economy ◽  
Economy Model ◽  
New Business ◽  
The Cost ◽  
Data Analytic

This research proposed a model to assist the design of the associated data architecture and data analytic to support talent forecast in the current accelerating changes in economy, industry and business change due to the accelerating pace of technological change. The emerging and re-emerging economy model were available, such as Industrial revolution 4.0, platform economy, sharing economy and token economy. Those were driven by new business model and technology innovation. An increase capability of technology to automate more jobs will cause a shift in talent pool and workforce. New business model emerge as the availabilityand the cost effective emerging technology, and as a result of emerging or re-emerging economic models. Both, new business model and technology innovation, create new jobs and works that have not been existed decades ago. The future workers will be faced by jobs that may not exist today. A dynamics model of inter-correlation of economy, industry, business model and talent forecast were proposed. A collection of literature review were conducted to initially validate the model.

CAD Of Anticorrosive Protection Of Steel Structures

2019 ◽  
pp. 18-23
Keyword(s):  
Protective Coating ◽  
Computer Aided Design ◽  
Steel Structures ◽  
Cost Effective ◽  
Operating Conditions ◽  
Computational Tool ◽  
Protection Method ◽  
Cost Effective Method ◽  
The Cost ◽  
Aided Design

The choice of cost-effective method of anticorrosive protection of steel structures is an urgent and time consuming task, considering the significant number of protection ways, differing from each other in the complex of technological, physical, chemical and economic characteristics. To reduce the complexity of solving this problem, the author proposes a computational tool that can be considered as a subsystem of computer-aided design and used at the stage of variant and detailed design of steel structures. As a criterion of the effectiveness of the anti-corrosion protection method, the cost of the protective coating during the service life is accepted. The analysis of existing methods of steel protection against corrosion is performed, the possibility of their use for the protection of the most common steel structures is established, as well as the estimated period of effective operation of the coating. The developed computational tool makes it possible to choose the best method of protection of steel structures against corrosion, taking into account the operating conditions of the protected structure and the possibility of using a protective coating.

Production of Asbestos-free Brake Pad Using Groundnut Shell as Filler Material

2018 ◽  
Vol 4 (12) ◽  
Author(s):  
W. C. Solomon ◽  
M. T. Lilly ◽  
J. I. Sodiki
Keyword(s):  
Phenolic Resin ◽  
Cost Effective ◽  
Filler Material ◽  
Particle Sizes ◽  
Brake Pad ◽  
Brake Pads ◽  
Environmental Friendly ◽  
Sieve Size ◽  
Groundnut Shell ◽  
The Cost

The development and evaluation of brake pads using groundnut shell (GS) particles as substitute material for asbestos were carried out in this study. This was with a view to harnessing the properties of GS, which is largely deposited as waste, and in replacing asbestos which is carcinogenic in nature despite its good tribological and mechanical properties. Two sets of composite material were developed using varying particle sizes of GS as filler material, with phenolic resin as binder with percentage compositions of 45% and 50% respectively. Results obtained indicate that the compressive strength and density increase as the sieve size of the filler material decreases, while water and oil absorption rates increase with an increase in sieve size of GS particle. This study also indicates that the cost of producing brake pad can be reduced by 19.14 percent if GS is use as filler material in producing brake pad. The results when compared with those of asbestos and industrial waste showed that GS particle can be used as an effective replacement for asbestos in producing automobile brake pad. Unlike asbestos, GS-based brake pads are environmental friendly, biodegradable and cost effective.

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